Support for rotatable spray member



Feb. 27, 1968 e. DUTCHER SUPPORT FOR ROTATABLE SPRAY MEMBER Filed Jan. 6, 1964 INVENTOR. MDZMGZ' llll llllltlllllllll Q United States Patent 3,379,869 SUPPORT FOR ROTATABLE SERAY MEMBER Ival G. Dutcher, White Bear Lake, Minn., assignor to Whirlpool Corporation, a corporation of Delaware Filed Jan. 6, 1964, Ser. No. 335,855 8 Claims. (Cl. 285-119) This invention relates to spray devices and in particular to means for sealing rotatable spray arms to a supporting hub in apparatus such as dishwashers.

L'1 one conventional form of dishwasher, such as disclosed in the copending application of Jack F. Clearman, Ser. No. 246,511, filed Dec. 21, 1963, and assigned to the assignee hereof, a spray arm is rotatably carried on a fixed hub at the bottom of a tub for spraying dish washing liquid upwardly into the tub to wash dishes and the like retained therein. The present invention comprehends an improved means for carrying a spray arm on a hub and may be advantageously employed in such apparatus.

Thus, a principal feature of the present invention is the provision of a new and improved spray device.

Another feature of the invention is the provision of such a spray device having new and improved means for carrying a spray arm upon a hub.

A further feature of the invention is the provision of such a spray device having a hub, a flow passage through the hub having an outlet for discharging fluid laterally therefrom, and a hollow spray arm, including means for mounting the spray arm rotatably on the hub, annular retaining means on the hub, means on the spray arm cooperating with the support means for retaining the spray arm rotatably on the hub, annular means on the spray arm extending circumjacent the hub, and an annular seal having an inner portion sli-dably rotatably engaging the hub and an outer portion adapted to be held in sealing engagement with the annular means on the spray arm by fluid pressure within the arm.

Still another feature of the invention is the provision of such a spray arm mounting means wherein the seal is formed of a flexible material to accommodate eccentricity and irregularities in the portions of the spray device engaged thereby.

A yet further feature of the invention is the provision of such a spray device having new and improved seal means arranged to be held in sealing engagement by the pressure of the fluid delivered therethrough.

A yet further feature of the invention is the provision of such a spray device wherein the seal provides an effectively minimum bearing surface for facilitated rotation of the spray arm.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein:

FIGURE 1 is a fragmentary diametric section of a dishwasher apparatus provided with a spray device embodying the invention;

FIGURE 2 is a fragmentary enlarged transverse section taken substantially along the line 2-2 of FIGURE 1;

FIGURE 3 is a fragmentary vertical section taken substantially along the line 33 of FIGURE 2; and

FIGURE 4 is a fragmentary section similar to that of a portion of FIGURE 3, but illustrating the installation of the seal on the spray arm.

In the exemplary embodiment of the invention as disclosed in the drawing, a dishwasher apparatus generally designated is shown to comprise a tub 11 having a bottom wall 12 carrying a conventional pump 13 provided with an outlet 14 for delivering washing liquid under pressure upwardly therefrom. A conventional electrical heating rod 15 may be installed above the bottom wall 12 for heating the washing liquid in the usual manner during selected cycles of operation of the dishwasher.

3,37,8fl9 Patented Feb. 27, 1968 The dish washing liquid is dispersed into the dish washing chamber 16 defined by the tub 11 by means of a spray arm assembly generally designated 17. As best seen in FIGURE 1, the spray arm assembly is carried on a hub 18 upstanding from the outlet 14 of the pump. The hub further carries a jet nozzle 19, as shown in FIGURE 3, the nozzle being provided at its upper end with a nozzle cap 29. The spray arm 17 includes an upper nozzle plate 21 having a downturned inner annular flange 22 received in an upwardly opening annular groove 23 in an upper portion 24 of the hub 18. As best seen in FIGURE 3, the nozzle cap includes an annular depending portion 25 overlying the nozzle plate to retain the flange 22 within the groove 23.

As shown in FIGURE 3, the spray arm defines a hollow interior 26 into which washing liquid is delivered through outlet openings 27 in the hub 18, the hub being provided with an axial bore 28 for conducting the washing liquid from the pump outlet 14 to the jet nozzle 19 and to the outlets 27.

The spray arm is further provided with a bottom plate 29 defining a radially inner annular flange 30 having an inner diameter slightly larger than the outer diameter of a concentric lower portion 31 of the hub 18 below the outlets 27. The flange 30 is sealingly connected to the hub portion 31 by means of an annular seal 32 formed of a material having a low coefficient of friction and having a radially extending portion 33 and an inner axial bearing surface 34. As shown in FIGURE 3, the inner surface 34 facially engages the hub portion 31 and the upper portion 33 facially engages the flange 30, The seal is preferably formed of a flexible material such as nylon and is provided with a plurality of L-shaped tabs 35, herein three, at degree circumferentially spaced positions on the lower end of the inner portion for retaining the seal in association with the flange 30 of the spray arm plate 29. As shown in FIGURE 4, the seal is readily installed on the flange 30 by flexing the seal sufficiently to urge the tabs radially inwardly to clear the inner end of the flange 30 and permit axial movement of the seal to the final position shown in dotted lines on FIGURE 4.

The assembly of the apparatus is extremely simple. Firstly, the jet nozzle 19 is attached to the hub 13 and the assembled jet nozzle and hub are then threaded onto the pump outlet 14, as shown in FIGURE 3. The seal 32 is then installed on the spray arm flange 30, as discussed above, and the spray arm is installed on the hub with the seal in engagement with portion 31 thereof and the flange 22 received in the upwardly opening groove 23 at the upper portion of the hub. The nozzle cap 20 is then threaded onto the hub to lock the spray arm in association with the hub.

When washing liquid is delivered from pump 13 upwardly through bore 28 and laterally outwardly through the outlet openings 27 into the spray arm 17, the pressure thereof within the spray arm interior 26 acts against the seal portion 33 to force it sealingly against the flange 36. The relatively low coeflicient of friction between the seal and the hub portion 31 permits the seal to adjust itself to permit the desired sealing engagement of the portion 33 with the flange 30. Further, the low coeflicient of friction permits the seal to rotate freely on the hub portion 31 with the spray arm. As the seal material is relatively flexible, the seal accommodates itself to irregularities in the surfaces of the hub portion 31 and flange 39 to assure a sealed connection of the spray arm to the hub notwithstanding the presence of such irregularities.

The axial length of seal leg portion 34 is preferably relatively small so that the areas of frictional engagement of the seal with the hub portion 31 is etfectively minimum, whereby improved facilitated rotation of the seal on the hub portion 31 is obtained.

Thus, the spray arm 17 is carried on the hub in a simple and economical manner by means of the improved seal structure 32. The seal structure is extremely simple and economical while yet assuring long trouble-free life and improved facilitated rotation of the spray arm in operation of the dishwasher. Still further, the spray device structure may be readily assembled and disassembled for facilitated maintenance.

While I have shown and described one embodiment of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a spray device having a hub, a flow passage through the hub having an outlet for discharging fluid laterally therefrom, and a hollow spray arm, means for supporting the spray'arm rotatably on the hub, comprising:

annular retaining means on the hub;

means on the spray arm cooperating with the supporting means for retaining the spray arm rotatably on the hub;

an annular flange on the spray arm extending circumjacent the hub;

an annular seal formed of a flexible material and having an inner portion slidably rotatably engaging the hub and extending between the hub and said annular flange, and an outer portion within said spray arm arranged to be held in sealing engagement with said annular flange on the spray arm directly by fluid pressure within said arm; and

means on the seal outwardly of said spray arm for retaining the seal in association with the spray arm.

2. The spray device of claim 1 wherein said seal retaining means includes one leg extending axially from said inner portion and a distal leg extending radially outwardly in axially spaced relation to said outer portion.

3. The spray device of claim 1 wherein said seal retaining means includes a plurality of tabs each including a portion resiliently joined to said inner portion and a distal portion adapted to engage releasably the spray arm. 4. The spray device of claim 3 wherein said distal leg is radially shorter than said outer portion for facilitated installation of the seal on said annular flange.

5. The spray device of claim 1 wherein said seal retaining means includes one leg extending axially from said inner portion and a distal leg extending radially outwardly in axially spaced relation to said outer portion,

said axial leg of the seal having an outer diameter slightly less than the inner diameter of said annular flange on the spray arm.

6. The spray device of claim 1 wherein said seal retaining means includes one leg extending axially from said inner portion and a distal leg extending radially outwardly in axially spaced relation to said outer portion, the axial length of said axial leg of the retaining portion being small.

7. The spray device of claim 4 wherein said seal is formed of nylon.

8. The spray device of claim 1 wherein said seal retaining means comprises an integral portion of said seal.

References Cited UNITED STATES PATENTS 1,180,167 3/1916 McMullan 239-259 1,705,016 3/1929 Jack 103-111 1,776,714 7 9/1930 Armstrong 285-281 2,266,223 12/1941 Lund 239-254. 2,520,896 8/1950 Smulski 285- 2,586,517 2/1952 Coles 285-281 2,647,002 7/ 1953 Brummer 277-178 2,987,260 6/1961 Sasnett 134-176 2,992,781 7/1961 Howard 239-251 3,064,665 11/1962 Martiniak 239-244 3,064,984 11/ 1962 Mickle 277-178 3,084,701 4/1963 Hardy 103-111 FOREIGN PATENTS 234,455 11/ 1925 Great Britain.

CARL W. TOMLIN, Primary Examiner.

R. GIANGIORGI, T. F. CALLAGHAN,

Assistant Examiners. 

1. IN A SPRAY DEVICE HAVING A HUB, A FLOW PASSAGE THROUGH THE HUB HAVING AN OUTLET FOR DISCHARGING FLUID LATERALLY THEREFROM, AND A HOLLOW SPRAY ARM, MEANS FOR SUPPORTING THE SPRAY ARM ROTATABLY ON THE HUB, COMPRISING: ANNULAR RETAINING MEANS TO THE HUB; MEANS ON THE SPRAY ARM COOPERATING WITH THE SUPPORTING MEANS FOR RETAINING THE SPRAY ARM ROTATABLY ON THE HUB; AN ANNULAR FLANGE ON THE SPRAY ARM EXTENDING CIRCUMJACENT THE HUB; AN ANNULAR SEAL FORMED OF A FLEXIBLE MATERIAL AND HAVING AN INNER PORTION SLIDABLY ROTATABLY ENGAGING THE HUB AND EXTENDING BETWEEN THE HUB AND SAID ANNULAR FLANGE, AND AN OUTER PORTION WITHIN SAID SPRAY ARM ARRANGED TO BE HELD IN SEALING ENGAGEMENT WITH SAID ANNULAR FLANGE ON THE SPRAY ARM DIRECTLY BY FLUID PRESSURE WITHIN SAID ARM; AND MEANS ON THE SEAL OUTWARDLY OF SAID SPRAY ARM FOR RETAINING THE SEAL IN ASSOCIATION WITH THE SPRAY ARM. 